A fascinating and open question challenging biochemistry, physics, and
even geometry is the presence of highly regular motifs such as a helices
in the folded state of biopolymers and proteins. Stimulating
explanations ranging from chemical propensity to simple geometrical
reasoning have been invoked to rationalize the existence of such
secondary structures. We formulate a dynamical variational principle for
selection in conformation space based on the requirement that the
backbone of the native state of biologically viable polymers be rapidly
accessible from the denatured state. The variational principle is shown
to result in the emergence of helical order in compact structures.
